And Iowa, with former Arkansas Governor Mike Huckabee not running, is tailor-made for Palin. Roughly 60% of the state's Republican caucus attenders will be evangelical Christians, a constituency that has in the past embraced Mrs. Palin as "one of their own."

A Palin candidacy would immediately benefit two men: Mitt Romney and Jon Huntsman. Mr. Romney would benefit from the narrative contrast -- him against her -- that might cause fence-sitting contributors and politicians to support Romney to stop Palin. Nothing panics veteran GOP pols like the idea of having Sarah Palin at the top of the 2012 presidential ticket. They think she can do serious damage to down-ballot candidates; candidates for governor and the US Senate and for Congress. Stopping that from happening is an absolutely urgent task for them. The only candidate who out-polls Palin at the moment is Romney. They know he might not win, but he won't bring with him collateral damage. For the time being, reducing collateral damage would be better than nothing.

Amb. Huntsman could benefit from the Romney-Palin narrative by adding a twist: "is this really the best we can do?" Mr. Huntsmanis proving to be a far more deft politician than many insiders expected. He has (basically) the old McCain campaign team working for him. That team knows how to run a "maverick" campaign to the nomination. And they know how to run against Mitt Romney.

The fact is that a large number of Republican politicians and, more important, Republican primary voters would like a fresh face, a solid conservative candidate who can take the fight to President Obama. That's what Amb. Huntsman is selling. With Palin soaking up the oxygen amongst social conservatives and Romney not exciting more "traditional" GOP voters, there's an opening for Huntsman to come in, defeat Romney and go on to defeat Palin.

Who would be hurt by Mrs. Palin's entrance into the race? First and foremost: former Minnesota Governor Tim Pawlenty. Mr. Pawlenty received a big lift when Mike Huckabee unexpectedly got out of the race. Social conservatives in Iowa, South Carolina and all across the South and the Midwest no longer had a champion. The Pawlenty brain trust saw their man as the one who could take up their banner. Combining that with his credibility among "traditional" Republicans, they reasoned, made him (potentially) formidable. They moved up his announcement of candidacy to fill the political vacuum created by Huckabee's departure. Suddenly, they had a believable narrative as to how their man might win the 2012 GOP presidential nomination.

If Palin does get in, that narrative is out the window. She'll be the champion of social conservatives, not Pawlenty. And from there, all of the doubts about Pawlenty's path to the nomination reassert themselves. Palin makes it harder for Pawlenty to raise money. She makes it harder for him to gather social conservative political support. She makes it really, really hard for him to get media attention. She's the media magnet. She's what they want.

As for the others, they're hanging by a thread as it is, so a Palin candidacy would only make their political doom more certain.